But the first three presenters during the opening session of the three-day ArcticNet conference in Ottawa sounded alarmed by the increasingly visible signs of Arctic warming and the limited amount of money that Canada will spend to understand what’s happening.

Ice has cracked up — once in a while taking Nunavut hunters with it. Lakes continue to dry up, while permafrost melts and the tundra is greening, 650 scientists, officials and northerners heard Dec. 15.

Observations from the ground in the Eastern Arctic, from places like Iqaluit — where ice in Frobisher Bay is only now forming — and views taken by satellites at 500 kilometres above the earth’s surface showed ArcticNet participants that ice formation in 2010 is abnormally slow.

So far this winter, it’s been “very, very slow,” and like last year “very late in freezing up,” said Trudy Wohlleben, an ice forecaster with the Canadian Ice Service.

The most “unusual things [are] going on in the winter,” Wohlleben said.

Nothing is progressing as it used to, she said, listing a string of peculiar happenings:

• air temperatures 20 C above normal at the beginning of the year in the Baffin Island communities of Clyde River and Qikiqtarjuaq;

• large ice cracks south of Resolute Bay last January, which caused a hunter to float off on an ice floe;

• and other cracks in land-fast ice spreading throughout the High Arctic islands, endangering research stations, causing problems for polar trekkers and swallowing up a Twin Otter.

This past spring, ice on Hudson Bay broke up three to four weeks earlier, and the Nares Strait between Ellesmere Island and Greenland, which usually freezes fast from February to July, never froze up solid.

This year, looking ahead into 2011, may carry similar surprises, with recent air temperatures 20 C registering above average over the Foxe Basin, Wohlleben said.

Weak ice could also lead to more storms as ice cracks cause water temperatures to warm and then lead to even more ice break-up and more storms in a frightening loop.

What’s needed is more monitoring with more remote sensing devices like the buoys dropped on ice lands earlier this year, she said.

More monitoring of lakes and other fresh waterways also needs to be done, because they’re good indicators of climate change, said Frederick Wrona from the University of Victoria.

In the western Arctic he’s seeing lakes slumping into the water, drained lakes and new pools of water forming on the land when permafrost melts.

“We have dramatic changes taking place,” with the Arctic becoming a place of rain instead of snow, said Wrona, who predicted that there will be more extreme events like floods in the Arctic’s future.

With 60 Arctic lakes slated for study, he’d like to place more buoys in the water to better gauge the changes going on.

And more money for Arctic science would also help Greg Henry from the University of British Columbia keep his research project going.

Henry, who has been studying vegetation across Canada’s Arctic for the past 20 years, seeing a major portion of this money dry up this year.

Henry looked at climate change and tundra vegetation in his six-year “Climate Change Impacts on the Canadian Arctic Tundra” project, which received $8 million in federal International Polar Year funds and support from ArcticNet’s research network.

From Kugluktuk to Kangiqsualujjuaq, more than 600 researchers, elders, students and local researchers looked at berry-producing plants, people who live in the North, such as the mountain cranberry (kimminaq), crowberry (paurngaq), blueberry (kigutangirnaq) and the cloudberry (aqpik).

Now there’s a group of trained and interested local researchers in place, but the money earmarked for this project has ended and is unlikely to start flowing again until 2017 when a string of research stations— linked to the new Arctic research station in Cambridge Bay— start up.

Canada should be spending more money on Arctic science as it did during the International Polar Year.

“We should be doing as much as we were getting in IPY,” he said, when Canada set aside $150 million for Arctic research.

The good news for Arctic scientists eager to learn more about climate change is that ArcticNet, which funds projects involving about 150 researchers across Canada, can expect to see some more money from the federal government.

As we wait to see if 2010 ends up as the Earth's warmest year on record, an intriguing series of maps from NASA's Goddard Institute for Space Studies shows how the average global temperature on Earth has increased by about 1.4 degrees since 1880 (click "play" under the map on the NASA page to see the animation).

Whether natural or man-made, NASA says the Earth is warmer today than it was 130 years ago.

The maps indicate temperature changes by decade, which show how much warmer or colder the world is compared to the "average" measured from 1951-1980. The map above shows the decade of 2000-2009.

While a one-degree global change sounds insignifcant, a one- to two-degree drop was all it took to plunge the Earth into the Little Ice Age, according to NASA. And a five-degree drop was enough to bury a large part of North America under a towering mass of ice 20,000 years ago.

According to the World Meteorological Organization, 2010 is "almost certain" to rank among the three hottest years on record, and 2001-2010 is undoubtedly the warmest 10-year period since the beginning of weather records in 1850.

Global climate data from January-November of this year should be released this week, while the final data from 2010 will be available in January.

A record high global 12 month running mean temperature for the period with instrumental data was reached in 2010 which is particularly meaningful because it occurs when the recent minimum of solar irradiance is having its maximum cooling effect, the researchers report. The scale of the La Nina Pacific Ocean cooling event now underway will determine where the calendar year of 2010 is placed, they state.

The paper, "Global surface temperature change" by James Hansen, Reto Ruedy, Makiko Sato, and Ken Lo, was published in Reviews of Geophysics.

The authors state “we conclude that there has been no reduction in the global warming trend of 0.15°C–0.20°C per decade that began in the late 1970s” .This analysis of global temperatures “gives the lie to the frequent assertion that “global warming stopped in 1998”” they comment. They add that it is possible to find “almost any trend for a limited period via judicious choice of start and end dates of a data set”. Furthermore they state that the view that the trend in global surface temperature has been nearly flat since the late 1990s “is not supported by our data”.

Hansen has been involved in an ongoing analysis of global temperatures at GISS since the late 1970s and the first GISS analysis was published in 1981. The GISS analysis looks at changes to the global mean land and ocean surface temperature rather than absolute temperatures and it shows, broadly, that there has been a 0.8C warming since 1880 and a 0.4C warming since 1980.

The new paper also sheds some light into why the analysis by the team at NASA's Goddard Institute of Space Studies (GISS) shows that 2005 was the warmest calendar year, while analysis by the UK Meteorology Office shows that 1998 was the warmest year – a key part of the argument that global warming has stopped. The main factor is the inclusion of estimated temperature change for the Arctic region by the NASA GISS team.

The authors make the point that communication of the status of global warming to the public has always been hampered by weather variability as perception tends to be strongly influenced by the latest local fluctuation. However, they believe this can be overcome by stressing the need to focus on the frequency and magnitude of warm and cold anomalies, which change noticeably on decadal time scales as global warming increases.

Oceanographer at AGU: Western Antarctic Peninsula is seeing "the highest increase in temperatures of anywhere on Earth."

“Warm waters carried by the Antarctic Circumpolar Current are brushing the ice front in the western part of the continent, in the area of the Bellingshausen Sea.” [Click to enlarge.]

Antarctica is disintegrating much faster than almost anybody imagined — see “Nothing in the natural world is lost at an accelerating exponential rate like this glacier.” In 2001, the IPCC “consensus” said neither Greenland nor Antarctica would lose significant mass by 2100. They both already are. As Penn State climatologist Richard Alley said in March 2006, the ice sheets appear to be shrinking “100 years ahead of schedule.”

A presentation Monday at the fall meeting of the American Geophysical Union sheds some light on the underlying cause of this rapid melt — the ice is being attacked from the bottom. Discovery News has the story:

Global warming is sneaky. For more than a century it has been hiding large amounts of excess heat in the world’s deep seas. Now that heat is coming to the surface again in one of the worst possible places: Antarctica.

New analyses of the heat content of the waters off Western Antarctic Peninsula are now showing a clear and exponential increase in warming waters undermining the sea ice, raising air temperatures, melting glaciers and wiping out entire penguin colonies.

“In the area I work there is the highest increase in temperatures of anywhere on Earth,” said physical oceanographer Doug Martinson of the Lamont-Doherty Earth Observatory. Martinson has been collecting ocean water heat content data for more than 18 years at Palmer Island, on the western side of the Antarctic Peninsula.

“Eighty-seven percent of the alpine glaciers are in retreat,” said Martinson of the Western Antarctic Peninsula. “Some of the Adele penguin colonies have already gone extinct.”

Martinson and his colleagues looked not only at their very detailed and mapped water heat data from the last two decades, but compared them with sketchier data from the past and deep ocean heat content measurements worldwide. All show the same rising trend that is being seen in Antarctica.

“When I saw that my jaw just dropped,” said Martinson. The most dramatic rise has happened since 1960, he said.

The figure comes from Lamont-Doherty Earth Observatory (via Columbia University’s Earth Institute blog), which quotes Martinson explaining, “This is like a huge freight of hot coals–fresh, hot water being delivered right to the the front door.”

So while global warming has continued its fitful warming of the temperature on Earth’s surface, the planet is warming from human-cause greenhouse gases just where climate science said it would — the oceans, which is where more than 90% of the warming was projected to end up (as we learned in two key 2009 papers, see “Skeptical Science explains how we know global warming is happening.“). The key findings in the second study are summed up in these two figures:

Total Earth Heat Content from 1950 to 2003 (Murphy 2009).

Time series of global mean heat storage (0–2000 m), measured in 108 Jm-2

This new finding makes action now to reduce greenhouse gas emissions all the more important because we’re already stuck with more melting to come:

What the rising water heat means, he said, is that even if humanity got organized and soon stopped emitting greenhouse gases, there is already too much heat in the oceans to stop a lot of impacts — like the melting of a huge amount of Antarctic ice.

“There’s the potential that we’re locked into long term sea level rise for a long time,” Martinson told Discovery News….

As for how fast the ice will melt and in what locations, that depends largely on whether the upwelling warm water comes in contact with the thick ice shelf that crowds the coast and holds the block the glaciers from reaching the sea.

That, in turn, depends on the winds which drive away the surface waters and make it possible for the deeper waters to rise to the surface, said senior researcher Robert Bindschadler of NASA’s Goddard Earth Science and Technology Center and the University of Maryland-Baltimore County.

“It can destroy the ice shelf if that heat can get to it,” said Bindschadler, who at the same meeting presented his work from the melting Pine Island Ice Shelf in Antarctica.

Now that the upwelling deep sea water is the clear cause of the melting ice shelf, rather than summer melt water, as had been thought in the past, it’s a question of how winds will change in a warming world and whether they will drive more warm water into the ice shelves.

The warming of West Antarctica is most worrisome (at least for this century) because it’s going to disintegrate long before the East Antarctic Ice Sheet does. Not only is the WAIS melting from underneath, it is, as I wrote in the “high water” part of my book, inherently less stable:

Perhaps the most important, and worrisome, fact about the WAIS is that it is fundamentally far less stable than the Greenland ice sheet because most of it is grounded far below sea level. The WAIS rests on bedrock as deep as two kilometers underwater. One 2004 NASA-led study found that most of the glaciers they were studying “flow into floating ice shelves over bedrock up to hundreds of meters deeper than previous estimates, providing exit routes for ice from further inland if ice-sheet collapse is under way.” A 2002 study in Science examined the underwater grounding lines–the points where the ice starts floating. Using satellites, the researchers determined that “bottom melt rates experienced by large outlet glaciers near their grounding lines are far higher than generally assumed.” And that melt rate is positively correlated with ocean temperature.

The warmer it gets, the more unstable WAIS outlet glaciers will become. Since so much of the ice sheet is grounded underwater, rising sea levels may have the effect of lifting the sheets, allowing more-and increasingly warmer-water underneath it, leading to further bottom melting, more ice shelf disintegration, accelerated glacial flow, and further sea level rise, and so on and on, another vicious cycle. The combination of global warming and accelerating sea level rise from Greenland could be the trigger for catastrophic collapse in the WAIS (see, for instance, here).

Times Topic: Global WarmingTHE earth continues to get warmer, yet it’s feeling a lot colder outside. Over the past few weeks, subzero temperatures in Poland claimed 66 lives; snow arrived in Seattle well before the winter solstice, and fell heavily enough in Minneapolis to make the roof of the Metrodome collapse; and last week blizzards closed Europe’s busiest airports in London and Frankfurt for days, stranding holiday travelers. The snow and record cold have invaded the Eastern United States, with more bad weather predicted.

All of this cold was met with perfect comic timing by the release of a World Meteorological Organization report showing that 2010 will probably be among the three warmest years on record, and 2001 through 2010 the warmest decade on record.

How can we reconcile this? The not-so-obvious short answer is that the overall warming of the atmosphere is actually creating cold-weather extremes. Last winter, too, was exceptionally snowy and cold across the Eastern United States and Eurasia, as were seven of the previous nine winters.

For a more detailed explanation, we must turn our attention to the snow in Siberia.

Annual cycles like El Niño/Southern Oscillation, solar variability and global ocean currents cannot account for recent winter cooling. And though it is well documented that the earth’s frozen areas are in retreat, evidence of thinning Arctic sea ice does not explain why the world’s major cities are having colder winters.

But one phenomenon that may be significant is the way in which seasonal snow cover has continued to increase even as other frozen areas are shrinking. In the past two decades, snow cover has expanded across the high latitudes of the Northern Hemisphere, especially in Siberia, just north of a series of exceptionally high mountain ranges, including the Himalayas, the Tien Shan and the Altai.

The high topography of Asia influences the atmosphere in profound ways. The jet stream, a river of fast-flowing air five to seven miles above sea level, bends around Asia’s mountains in a wavelike pattern, much as water in a stream flows around a rock or boulder. The energy from these atmospheric waves, like the energy from a sound wave, propagates both horizontally and vertically.

As global temperatures have warmed and as Arctic sea ice has melted over the past two and a half decades, more moisture has become available to fall as snow over the continents. So the snow cover across Siberia in the fall has steadily increased.

The sun’s energy reflects off the bright white snow and escapes back out to space. As a result, the temperature cools. When snow cover is more abundant in Siberia, it creates an unusually large dome of cold air next to the mountains, and this amplifies the standing waves in the atmosphere, just as a bigger rock in a stream increases the size of the waves of water flowing by.

The increased wave energy in the air spreads both horizontally, around the Northern Hemisphere, and vertically, up into the stratosphere and down toward the earth’s surface. In response, the jet stream, instead of flowing predominantly west to east as usual, meanders more north and south. In winter, this change in flow sends warm air north from the subtropical oceans into Alaska and Greenland, but it also pushes cold air south from the Arctic on the east side of the Rockies. Meanwhile, across Eurasia, cold air from Siberia spills south into East Asia and even southwestward into Europe.

That is why the Eastern United States, Northern Europe and East Asia have experienced extraordinarily snowy and cold winters since the turn of this century. Most forecasts have failed to predict these colder winters, however, because the primary drivers in their models are the oceans, which have been warming even as winters have grown chillier. They have ignored the snow in Siberia.

Last week, the British government asked its chief science adviser for an explanation. My advice to him is to look to the east.

It’s all a snow job by nature. The reality is, we’re freezing not in spite of climate change but because of it.

Judah Cohen is the director of seasonal forecasting at an atmospheric and environmental research firm.

UXBRIDGE, Canada - The world's northern freezer is on rapid defrost as large volumes of warm water are pouring into the Arctic Ocean, speeding the melt of sea ice, according to a new study.

[The world's northern freezer is on rapid defrost as large volumes of warm water are pouring into the Arctic Ocean, speeding the melt of sea ice, according to a new study. (NASA Goddard Photo)]The world's northern freezer is on rapid defrost as large volumes of warm water are pouring into the Arctic Ocean, speeding the melt of sea ice, according to a new study. (NASA Goddard Photo)

Surface temperatures in parts of the Arctic have been 21 degrees C above normal for more than a month in recent weeks.

"Boats were still in the water during the first week of January," said David Phillips, a senior climatologist with Environment Canada, referring to southern Baffin Island, some 2,000 km north of Montreal. This is a region that receives just four or five hours of weak sunlight during the long winter. Temperatures normally range from -25 to -35 degrees C but were above zero on some days in January.

"It's impossible for many people in parts of the eastern Arctic to safely get on the ice to hunt much-needed food for their families - for the second winter in a row," Phillips said in a report.

The warming and melting of the Arctic is happening much faster than expected and new data reveals that huge volumes of warmer water from the North Atlantic are now flowing into and warming up the Arctic Ocean, researchers reported Friday in the journal Science.

"In the past hundred years the waters in the Fram Strait have warmed about two degrees C," says co-author Thomas Marchitto, of Colorado University's Institute of Arctic and Alpine Research.

The Fram Strait between Greenland and Svalbard (Spitsbergen) is the major connection between the Arctic Ocean and the world ocean. An international team of researchers analysed marine sediments and found that temperatures of the northward inflowing Atlantic water varied by just a few tenths of a degree Celsius during the past 2,000 years. However, in the last hundred years temperatures have shot up by two degrees C.

"What's happening here is very unusual compared to the last 2,000 years," Marchitto told IPS.

Climate change is believed to be behind this warmer water because over 90 percent of additional heat trapped in the atmosphere from the burning of fossil fuels like coal, oil and natural gas is going into the oceans, he said.

"The accelerated decrease of the Arctic sea ice cover and the warming of ocean and atmosphere in the Arctic, as measured during the past decades, are in part related to an increased heat transfer from the Atlantic," said co-author Robert Spielhagen, a palaeoceanographer at the Academy of Sciences, Humanities and Literature in Mainz, Germany.

Sea ice has declined dramatically during the short Arctic summers in recent years, with some experts now projecting that the ice cover will be essentially gone in as little as five years. Just a few years ago, no one thought a summer ice-free Arctic could happen before 2060.

The warming Arctic and melting sea ice is a planetary-scale change since the Arctic Ocean covers 14 million sq km, an area almost as big as Russia. The Arctic and Antarctic polar regions are key drivers of Earth's weather and climate. The rapid defrosting of the Arctic has already altered the climate system, researchers now agree.

IPS previously broke the story revealing that the snow and cold in the eastern United States and Europe during the winter of 2009-10 was likely the result of the loss of Arctic sea ice. The same thing has happened this year.

As more and more sea ice melts, there is more open water to absorb the summer sun's heat. A day of 24-hour summer sun in the Arctic puts more heat on the surface of the ocean than a day in the tropics, James Overland of the NOAA/Pacific Marine Environmental Laboratory in the United States told IPS.

That extra heat in the ocean is gradually released into the lower atmosphere from October to January as the region slowly re-freezes months later than normal. This is a fundamental change - a large part of the Arctic Ocean is radiating heat instead of being cold and ice-covered. That has disrupted wind circulation patterns in the northern hemisphere, reported Overland and other researchers at the International Polar Year Oslo Science Conference in Norway last June.

The result: the Arctic stays warm and mid-latitude regions become colder and receive more snow for much of the winter. Last December was the coldest south Florida has experienced in more than a century of record-keeping.

Most of Britain suffered through its coldest December ever. Up in the Arctic, Coral Harbour on the northwest corner of Hudson Bay was above zero degrees C for two days in early January for the first time in history. Much of the eastern Arctic centred around Baffin Island averaged +21C above normal between Dec. 17 and Jan. 15 this year.

This looks to be the new normal since Arctic experts agree the melting sea ice is now locked into a death spiral.

"In future, cold and snowy winters will be the rule rather than the exception" in the eastern United States and Europe, Overland previously told IPS.

This week the U.S. northeast suffered through its sixth major snowstorm this winter, breaking all snowfall records.

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Arctic Current Warmest In Over 2,000 Years, Warning Of Ice-FMon Jan 31, 2011 7:56 pm

OSLO (Reuters/Alister Doyle) - A North Atlantic current flowing into the Arctic Ocean is warmer than for at least 2,000 years in a sign that global warming is likely to bring ice-free seas around the North Pole in summers, a study showed.

Scientists said that waters at the northern end of the Gulf Stream, between Greenland and the Norwegian archipelago of Svalbard, averaged 6 degrees Celsius (42.80F) in recent summers, warmer than at natural peaks during Roman or Medieval times.

"The temperature is unprecedented in the past 2,000 years," lead author Robert Spielhagen of the Academy of Sciences, Humanities and Literature in Mainz, Germany, told Reuters of the study in Friday's edition of the journal Science.

The summer water temperatures, reconstructed from the makeup of tiny organisms buried in sediments in the Fram strait, have risen from an average 5.2 degrees Celsius (41.36F) from 1890-2007 and about 3.4C (38.12F) in the previous 1,900 years.

The findings were a new sign that human activities were stoking modern warming since temperatures are above past warm periods linked to swings in the sun's output that enabled, for instance, the Vikings to farm in Greenland in Medieval times.

"We found that modern Fram Strait water temperatures are well outside the natural bounds," Thomas Marchitto, of the University of Colorado at Boulder, one of the authors, said in a statement.

The Fram strait is the main carrier of ocean heat to the Arctic.

ICE-FREE OCEAN

The authors wrote that the warming temperatures "are presumably linked to the Arctic amplification of global warming" and that the warming "is most likely another key element in the transition to a future ice-free Arctic Ocean."

Ice on the Arctic Ocean shrank to its lowest on record in 2007 and many experts expect the ocean will be ice-free in summers in coming decades, a threat to the hunting livelihoods of indigenous peoples and to creatures such as polar bears.

The Arctic is heating up twice as fast as the global average as part of a trend the U.N. panel of climate scientists blames on a build-up of greenhouse gases from mankind's use of fossil fuels in power plants, factories and cars.

The shrinking of reflective ice and snow in the Arctic region exposes water or ground which are darker colored and so soak up more heat from the sun, amplifying warming.

Billions of trees died in the record drought that struck the Amazon in 2010, raising fears that the vast forest is on the verge of a tipping point, where it will stop absorbing greenhouse gas emissions and instead increase them.

The dense forests of the Amazon soak up more than one-quarter of the world's atmospheric carbon, making it a critically important buffer against global warming. But if the Amazon switches from a carbon sink to a carbon source that prompts further droughts and mass tree deaths, such a feedback loop could cause runaway climate change, with disastrous consequences.

"Put starkly, current emissions pathways risk playing Russian roulette with the world's largest forest," said tropical forest expert Simon Lewis, at the University of Leeds, and who led the research published today in the journal Science. Lewis was careful to note that significant scientific uncertainties remain and that the 2010 and 2005 drought – thought then to be of once-a-century severity – might yet be explained by natural climate variation.

"We can't just wait and see because there is no going back," he said. "We won't know we have passed the point where the Amazon turns from a sink to a source until afterwards, when it will be too late."

Alex Bowen, from the London School of Economics and Political Science's Grantham research institute on climate change, said huge emissions of carbon from the Amazon would make it even harder to keep global greenhouse gases at a low enough level to avoid dangerous climate change. "It therefore makes it even more important for there to be strong and urgent reductions in man-made emissions."

The revelation of mass tree deaths in the Amazon is a major blow to efforts to reduce the destruction of the world's forests by loggers, one of the biggest sources of global carbon emissions. The use of satellite imagery by Brazilian law enforcement teams has drastically cut deforestation rates and replanting in Asia had slowed the net loss. Financial deals to protect forests were one of the few areas on which some progress was made at the 2010 UN climate talks in Cancún.

The 2010 Amazonian drought led to the declaration of states-of-emergencies and the lowest ever level of the major tributary, the Rio Negro. Lewis, with colleagues in Brazil, examined satellite-derived rainfall measurements and found that the 2010 drought was even worse than the very severe 2005 drought, affecting a 60% wider area and with an even harsher dry season.

On the ground, the researchers have 126 one-hectare plots spread across the Amazon, in which every single tree is tagged and monitored. After 2005, they counted how many trees had died and worked out how much carbon would be pumped into the atmosphere as the wood rotted. In addition, the reduced growth of the water-stressed trees means the forest failed to absorb the 1.5bn tonnes of carbon that it would in a normal year.

Applying the same principles to the 2010 drought, they estimated that 8.5 billion tonnes of CO2 will be released - more than the entire 7.7bn tonnes emitted in 2009 by China, the biggest polluting nation in the world. This estimate does not include forest fires, which release carbon and increase in dry years.

"The Amazon is such a big area that even a small shift [in conditions] there can have a global impact," said Lewis.

Lewis said that two such severe droughts in the Amazon within five years was highly unusual, but that a natural variation in climate over decade-long periods cannot yet be ruled out. The driving factor of the annual weather patterns is the warmth of the sea in the Atlantic. He said increasing droughts in the Amazon are found in some climate models, including the sophisticated model used by the Hadley centre. This means the 2005 and 2010 droughts are consistent with the idea that global warming will cause more droughts in future, emit more carbon, and potentially lead to runaway climate change. "The greenhouse gases we have already emitted may mean there are several more droughts in the pipeline," he said.

Lewis said that the 2010 drought killed "in the low billions of trees", in addition to the roughly 4 billion trees that die on average in a normal year across the Amazon. The researchers are now trying to raise £500,000 in emergency funding to revisit the plots in the Amazon and gather further data.

Brazilian scientist Paulo Brando, from the Instituto de Pesquisa Ambiental da Amazônia (Amazon Environmental Research Institute), and co-leader of the research said: "We will not know exactly how many trees were killed until we can complete forest measurements on the ground. It could be that many of the drought-susceptible trees were killed off in 2005. Or the first drought may have weakened a large number of trees so increasing the number dying in 2010."

Brando added: "Our results should be seen as an initial estimate. The emissions estimates do not include those from forest fires, which spread over extensive areas of the Amazon during hot and dry years and release large amounts of carbon."

Climate tipping points

Scientists know from the geological record that the Earth's climate can change rapidly. They have identified a number of potential tipping points where relatively small amounts of global warming caused by human activities could cause large changes in climate. Some tipping points, like the losses to the Amazon forests, involve positive feedback loops and could lead to runaway climate change.

Arctic ice cap: The white ice cap is good at reflecting the Sun's warming light back into space. But when it melts, the dark ocean uncovered absorbs this heat. This leads to more melting, and so on.

Tundra: The high north is warming particularly fast, melting the permafrost that has locked up vast amounts of carbon in soils for thousands of years. Bacteria digesting the unfrozen soils generate methane, a potent greenhouse gas, leading to more warming.

Gas hydrates: Also involving methane, this tipping point involves huge reservoirs of methane frozen on or just below the ocean floor. The methane-water crystals are close to their melting point and highly unstable. A huge release could be triggered by a little warming.

West Antarctic ice sheet: Some scientists think this enormous ice sheet, much of which is below sea level, is vulnerable to small amounts of warming. If it all eventually melted, sea level would rise by six metres.

WASHINGTON — Extreme rainstorms and snowfalls have grown substantially stronger, two studies suggest, with scientists for the first time finding the telltale fingerprints of man-made global warming on downpours that often cause deadly flooding.

Two studies in Wednesday's issue of the journal Nature link heavy rains to increases in greenhouse gases more than ever before.

One group of researchers looked at the strongest rain and snow events of each year from 1951 to 1999 in the Northern Hemisphere and found that the more recent storms were 7 percent wetter. That may not sound like much, but it adds up to be a substantial increase, said the report from a team of researchers from Canada and Scotland.

The study didn't single out specific storms but examined worst-of-each-year events all over the Northern Hemisphere. While the study ended in 1999, the close of the decade when scientists say climate change kicked into a higher gear, the events examined were similar to more recent disasters: deluges that triggered last year's deadly floods in Pakistan and in Nashville, Tenn., and this winter's paralyzing blizzards in parts of the United States.

The change in severity was most apparent in North America, but that could be because that's where the most rain gauges are, scientists said.

Both studies should weaken the argument that climate change is a "victimless crime," said Myles Allen of the University of Oxford. He co-authored the second study, which connected flooding and climate change in the United Kingdom. "Extreme weather is what actually hurts people."

Jonathan Overpeck, a University of Arizona climate scientist, who didn't take part in either study, praised them as sensible and "particularly relevant given the array of extreme weather that we've seen this winter and stretching back over the last few years."

Not all the extreme rain and snow events the scientists studied cause flooding. But since 1950, flooding has killed more than 2.3 million people, according to the World Health Organization's disaster database.

The British study focused on flooding in England and Wales in the fall of 2000. The disaster cost more than $1.7 billion in insured damages and was the wettest autumn for the region in more than 230 years of record-keeping.

Researchers found that global warming more than doubled the likelihood of that flood occurring. Similar studies are now under way to examine whether last year's deadly Russian heat wave and Pakistan floods – which were part of the same weather event – can be scientifically attributed to global warming.

For years scientists, relying on basic physics and climate knowledge, have said global warming would likely cause extremes in temperatures and rainfall. But this is the first time researchers have been able to point to a demonstrable cause-and-effect by using the rigorous and scientifically accepted method of looking for the "fingerprints" of human-caused climate change.

The scientists took all the information that shows an increase in extreme rain and snow events from the 1950s through the 1990s and ran dozens of computer models numerous times. They put in the effects of greenhouse gases – which come from the burning of fossil fuels – and then ran numerous models without those factors. Only when the greenhouse gases are factored in do the models show a similar increase to what actually happened. All other natural effects alone don't produce the jump in extreme rainfall. Essentially, the computer runs show climate change is the only way to explain what's happening.

In fact, the computer models underestimated the increase in extreme rain and snow. That is puzzling and could be even more troubling for our future, said Michael Oppenheimer of Princeton University, who wasn't part of the study.

Similar fingerprinting studies have found human-caused greenhouse gas emissions triggered changes in more than a dozen other ecological ways: temperatures on land, the ocean's surface, heat content in the depths of the oceans, temperature extremes, sea level pressure, humidity at ground level and higher in the air, general rainfall amounts, the extent of Arctic sea ice, snowpack levels and timing of runoff in the western United States, Atlantic Ocean salinity, wildfire damage, and the height of the lower atmosphere.

All those signs say global warming is here, said Xuebin Zhang, a research scientist for the Canadian government and co-author of the Northern Hemisphere study. "It is affecting us in multiple directions."

Most of the 10 outside climate experts who reviewed the papers for The Associated Press called the research sound and strong.

However, climate scientist Jerry North of Texas A&M University, while praising the work, said he worried that the studies were making too firm a connection based on weather data that could be poor in some locations. But Francis Zwiers of the University of Victoria, a lead author of the study with Zhang, said the data was from National Weather Service gauges and is reliable.

"Put the two papers together and we start to see an emerging pattern," said Andrew Weaver of the University of Victoria, who wasn't part of either study. "We should continue to expect increased flooding associated with increased extreme precipitation because of increasing atmospheric greenhouse gas. And we have no one to blame but ourselves."
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ELEANOR HALL: A study by researchers at the National Snow and Ice Data Center at the University of Colorado warns that two-thirds of the Earth's permafrost could disappear by 2200.

They say that would unleash vast amounts of carbon into the atmosphere and that this process would begin within 15 years.

Permafrost is permanently frozen ground that stores carbon from plant material which was frozen during the last Ice Age.

The researchers say that as the permafrost melts it will release thousands of years worth of carbon and accelerate global warming.

One of the researchers scientist Kevin Shaefer told Alison Caldwell that this study should influence the international strategies for dealing with climate change.

KEVIN SHAEFER: Permafrost is ground that's permanently frozen. In the Tundra regions in the very top of the soil you've got vegetation. And underneath that you've got a surface layer of soil that thaws each summer and freezes each winter.

Underneath that is permanently frozen ground or permafrost.

ALISON CALDWELL: What's inside it? What does, does it store anything?

KEVIN SHAEFER: This permafrost contains carbon that's been frozen since the last Ice Age.

To get an idea of what this looks like you can go to your backyard and pick up a handful of dirt and just freeze it. And the organic matter, everything, that's what permafrost looks like.

Now in the future when temperatures increase the depth of thawing each summer is going to get deeper and deeper and deeper. And eventually this frozen carbon, this frozen organic matter will thaw out. Once it thaws out it will decay and end up in the atmosphere.

ALISON CALDWELL: Now you say in the future, what are we talking - 50, 100 years?

KEVIN SHAEFER: We estimate that this carbon will really begin to thaw out in about 15 or 20 years.

ALISON CALDWELL: That's not that far away.

KEVIN SHAEFER: No compared to how long it took to freeze it into the ground, it's coming up very fast, yes.

ALISON CALDWELL: How long did it take to freeze into the ground?

KEVIN SHAEFER: Twenty, 30,000 years. Compared to how long it took to freeze that carbon into the ground it's all going to thaw out in 200 years, in the blink of an eye geologically speaking.

ALISON CALDWELL: What percentage or what proportion of the Earth's permafrost are you saying will disappear by 2200?

KEVIN SHAEFER: Well we're looking at permafrost only in the high northern latitudes. And we predict between 29 and 59 per cent of the permafrost will disappear by 2200. So that's between a third and two-thirds of the permafrost will just plain disappear.

ALISON CALDWELL: So how much carbon are we talking about?

KEVIN SHAEFER: We estimate by 2200, 190 gigatonnes plus or minus 64 gigatonnes of carbon will be released from the permafrost.

Now this is a lot of carbon. This is equivalent to roughly half of all fossil fuel emissions to date from the dawn of the industrial age.

Take the total fossil fuel emissions from power plants in the United States today and run them for another 80 years and that's how much carbon is going to be released from the permafrost.

Once it's released into the atmosphere it'll amplify the warming due to the release of fossil fuels and it'll accelerate the warming.

ALISON CALDWELL: So how did you reach this conclusion?

KEVIN SHAEFER: We ran a series of model projections out into the future.

We used the Intergovernmental Panel on Climate Change scenarios of emissions of fossil fuels into the future.

A bunch of models used that as input and then we took the output from those models and ran our permafrost model with permafrost carbon and then predicted how much permafrost would disappear and how much the carbon would thaw out and end up in the atmosphere.

ALISON CALDWELL: Now of course the sceptics would jump on the fact that you've used the Intergovernmental Panel on Climate Change models and they'd say those are dodgy.

KEVIN SHAEFER: They may or may not be dodgy but they're our best estimates of what might happen in the future.

As someone said, predictions are very difficult, especially about the future.

ALISON CALDWELL: The US Government, the Australian Government, the Canadian Government, they're all just talking about strategies to deal with climate change and they won't do anything unless someone else does. Does that concern you when you know what you have found?

KEVIN SHAEFER: Yes it does concern me. The only way to avoid the release of all this carbon is to reduce our fossil fuel emissions.

If you reduce emissions then the thawing of the permafrost will slow down and the start of this feedback would be pushed off into the future. So we really must reduce our fossil fuel emissions.

ALISON CALDWELL: How much time have governments got to do that?

KEVIN SHAEFER: I would say we should start right now.

What we feel our primary findings are is that there is a lot of carbon that could be emitted from the permafrost, enough to influence global strategies to reduce fossil fuel emissions.

And by that I mean if we want to hit some target atmospheric CO2 concentration, which means we want to hit a target climate, we have to account for the release of carbon from permafrost. Otherwise we will overshoot our target climate and end up with a warmer earth than we want.

ELEANOR HALL: That's scientist Kevin Shaefer from the National Snow and Ice Data Center at the University of Colorado. He was speaking about that permafrost research to Alison Caldwell.

WASHINGTON (Reuters/Deborah Zabarenko) - Rising seas spurred by climate change could threaten 180 U.S. coastal cities by 2100, a new study says, with Miami, New Orleans and Virginia Beach among those most severely affected.

Previous studies have looked at where rising waters might go by the end of this century, assuming various levels of sea level rise, but this latest research focused on municipalities in the contiguous 48 states with population of 50,000 or more.

Cities along the southern Atlantic coast and the Gulf of Mexico will likely be hardest hit if global sea levels rise, as projected, by about 3 feet (1 meter) by 2100, researchers reported in the journal Climate Change Letters.

Sea level rise is expected to be one result of global warming as ice on land melts and flows toward the world's oceans.

Using data from the U.S. Geological Survey, the scientists were able to calculate in detail how much land could be lost as seas rise, said study author Jeremy Weiss of the University of Arizona.

Rising coastal waters threaten an average of nine percent of the land in the 180 coastal cities in the study.

Miami, New Orleans, Tampa, Florida, and Virginia Beach, Virginia could lose more than 10 percent of their land area by century's end, the study found.

New York City, Washington DC and the San Francisco Bay area could face lesser impacts, according to the study.

CLIMATE CHANGE

The effects of higher seas can range from erosion to permanent inundation, and the severity of the damage depends in great measure on where the cities are, Weiss said by telephone on Wednesday.

"In Miami, it's not just strictly along their coastal edge. They have to worry about the issue in all directions," because much of the area around Miami is relatively flat, making it more vulnerable to encroaching waters, Weiss said.

By contrast, he said, people in the New York metropolitan area can concentrate their efforts along the shorelines because the land rises quickly away from the coast.

Sea level rise is expected as a consequence of continuing climate change, which is spurred by human activities including the burning of fossil fuels.

The U.N. Intergovernmental Panel on Climate Change IPCC.L has estimated global average temperature will rise by 3.6 degrees F (2 degrees C) by 2100. However, Weiss and his colleagues put the warming at more like 8 degrees F (4.4 degrees C).

Weiss said the lesser degree of warming projected by the IPCC reflects a moderate scenario. The study's higher temperature estimate is based on the idea that greenhouse emissions will continue along the current trajectory through the century.

A recent study has found that all of the world's coral reefs could be gone by 2050. If lost, 500 million people's livelihoods worldwide would be threatened.

The World Resources Institute report, "Reefs at Risk Revisited," suggests that by 2030, over 90 percent of coral reefs will be threatened. If action isn't taken soon, nearly all reefs will be threatened by 2050. Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration states, "Threats on land, along the coast and in the water are converging in a perfect storm of threats to reefs."

The AFP suggests that these threats include overfishing, coastal development, pollution, and climate change. Warming sea temperatures lead to coral bleaching, a stress response where corals expose their white skeletons. In 2005, the Caribbean saw the most extensive coral bleaching event ever recorded, often attributed to rising ocean temperatures. CO2 emissions are also making the oceans more acidic. Because of the rising acidity levels, some scientists claim we will see conditions not witnessed since the period of dinosaurs.

Lauretta Burke, one of the report's lead authors, feels that quick action could help save the reefs. She encourages policymakers to reduce overfishing and cut greenhouse gas emissions. If action is not taken though, millions of people will suffer. Shorelines will lose protection from storms -- a Time Magazine post suggests that up to 90 percent of the energy from wind generated waves is absorbed by reef ecosystems. If reefs are lost, coastal communities will lose a source of food security and tourism.

Vast ice sheets in Greenland and Antarctica are melting much more rapidly than predicted by climate models, according to scientists at NASA’s Jet Propulsion Laboratory in California.

Their NASA-funded study used two separate satellite observation systems over the past 20 years and found that the melting is accelerating.

Writing in the journal Geophysical Research Letters, researcher Eric Rignot says the Greenland-Antarctica melt is overtaking ice loss from mountain glaciers and other ice caps as the dominant influence on sea level rise.

He adds that if the ice cap melting continues unabated, it could add an additional 5.9 inches to the average global sea level by 2050.

JPL scientist Isabella Velicogna says that while six more inches in sea level heights might not sound that much, the increase will be distributed unevenly around the world, with low-lying countries like Bangladesh being impacted the most.

And when added to the predicted sea level rise of 6.6 inches from glacial melt and thermal ocean expansion as the climate warms, the total sea level rise could reach almost 12.6 inches, the researchers warn.

A new NASA study finds that the Greenland and Antarctic ice sheets are melting at an accelerating pace, three times faster than that of mountain glaciers and ice caps.

Arctic on the verge of record ozone loss
Arctic-wide measurements verify rapid depletion in recent days

Potsdam/Bremerhaven, March 14th, 2011. Unusually low temperatures in the Arctic ozone layer have recently initiated massive ozone depletion. The Arctic appears to be heading for a record loss of this trace gas that protects the Earth's surface against ultraviolet radiation from the sun. This result has been found by measurements carried out by an international network of over 30 ozone sounding stations spread all over the Arctic and Subarctic and coordinated by the Potsdam Research Unit of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association (AWI) in Germany.

"Our measurements show that at the relevant altitudes about half of the ozone that was present above the Arctic has been destroyed over the past weeks," says AWI researcher Markus Rex, describing the current situation. "Since the conditions leading to this unusually rapid ozone depletion continue to prevail, we expect further depletion to occur." The changes observed at present may also have an impact outside the thinly populated Arctic. Air masses exposed to ozone loss above the Arctic tend to drift southwards later. Hence, due to reduced UV protection by the severely thinned ozone layer, episodes of high UV intensity may also occur in middle latitudes. "Special attention should thus be devoted to sufficient UV protection in spring this year," recommends Rex.

Ozone is lost when breakdown products of anthropogenic chlorofluorocarbons (CFCs) are turned into aggressive, ozone destroying substances during exposure to extremely cold conditions. For several years now scientists have pointed to a connection between ozone loss and climate change, and particularly to the fact that in the Arctic stratosphere at about 20km altitude, where the ozone layer is, the coldest winters seem to have been getting colder and leading to larger ozone losses. "The current winter is a continuation of this development, which may indeed be connected to global warming," atmosphere researcher Rex explains the connection that appears paradoxical only at first glance. "To put it in a simplified manner, increasing greenhouse gas concentrations retain the Earth's thermal radiation at lower layers of the atmosphere, thus heating up these layers. Less of the heat radiation reaches the stratosphere, intensifying the cooling effect there." This cooling takes place in the ozone layer and can contribute to larger ozone depletion. "However, the complicated details of the interactions between the ozone layer and climate change haven't been completely understood yet and are the subject of current research projects," states Rex. The European Union finances this work in the RECONCILE project, a research programme supported with 3.5 million euros in which 16 research institutions from eight European countries are working towards improved understanding of the Arctic ozone layer.

In the long term the ozone layer will recover thanks to extensive environmental policy measures enacted for its protection. This winter's likely record-breaking ozone loss does not alter this expectation. "By virtue of the long-term effect of the Montreal Protocol, significant ozone destruction will no longer occur during the second half of this century," explains Rex. The Montreal Protocol is an international treaty adopted under the UN umbrella in 1987 to protect the ozone layer and for all practical purposes bans the production of ozone-depleting chlorofluorocarbons (CFCs) worldwide today. CFCs released during prior decades however, will not vanish from the atmosphere until many decades from now. Until that time the fate of the Arctic ozone layer essentially depends on the temperature in the stratosphere at an altitude of around 20 km and is thus linked to the development of earth's climate.

(CNN) -- The depletion of the ozone layer over the Arctic region "has reached an unprecedented level," a loss of 40% from the beginning of the winter to late March, the U.N. weather agency said Tuesday.

The World Meteorological Organization blames the "record loss" on the "continuing presence of ozone-depleting substances in the atmosphere" and a "very cold winter in the stratosphere."

The ozone layer is the "shield that protects life on Earth from harmful levels of ultraviolet rays," the organization said.

"Even though this Arctic winter was warmer than average at ground level, it was colder in the stratosphere than for a normal Arctic winter," the agency said.

"Although the degree of Arctic ozone destruction in 2011 is unprecedented, it is not unexpected. Ozone scientists have foreseen that significant Arctic ozone loss is possible in the case of a cold and stable Arctic stratospheric winter."

The highest ozone losses previously recorded were about 30% over several winter seasons in the last two decades.

An international agreement -- the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer -- has led to cuts in production of ozone-destroying chemicals.

"Without the Montreal Protocol, this year's ozone destruction would most likely have been worse. The slow recovery of the ozone layer is due to the fact that ozone-depleting substances stay in the atmosphere for several decades," the World Meteorological Organization said.

Ozone-depleting substances include chlorofluorocarbons and halons, once present in refrigerators, spray cans and fire extinguishers and which have been phased out under the 1987 Montreal Protocol.

Ultraviolet rays "have been linked to skin cancer, cataracts and damage to the human immune system. Some crops and forms of marine life can also suffer adverse effects," the U.N. agency said.

"The Arctic stratosphere continues to be vulnerable to ozone destruction caused by ozone-depleting substances linked to human activities," said Michel Jarraud, the agency's secretary-general.

"The degree of ozone loss experienced in any particular winter depends on the meteorological conditions. The 2011 ozone loss shows that we have to remain vigilant and keep a close eye on the situation in the Arctic in the coming years," he said.

The meteorological conditions in the Arctic vary every year. "Some Arctic winters experience almost no ozone loss, whereas cold stratospheric temperatures in the Arctic lasting beyond the polar night can occasionally lead to substantial ozone loss," the agency said.